Method, system, and product for indicating power status of field replaceable units

ABSTRACT

A method, system, and product are disclosed for indicating a power status of multiple devices using hierarchically encoded indicators. Multiple nodes are included within a data processing system. Each node includes a different implementation of the devices. Each one of a first level of power indicators are associated with a different one of the nodes. Each one of a second level of power indicators is associated with a different one of the devices. A power status of each node is indicated utilizing one of the first level of power indicators. A power status of each device is indicated utilizing the second level of power indicators.

CROSS-REFERENCE TO RELATED APPLICATIONS

This subject matter of the present application is related to commonlyassigned and co-pending U.S. patent application Ser. No. 10/755,876,entitled METHOD, SYSTEM, AND PRODUCT FOR HIERARCHICAL ENCODING OF FIELDREPLACEABLE UNIT SERVICE INDICATORS, filed on the same date herewith,assigned to the same assignee hereof, and hereby incorporated byreference.

BACKGROUND OF THE INVENTION

1. Technical Field

The present invention relates generally to an improved data processingsystem, and in particular to a method, system, and product forindicating power status for field replaceable units (FRUs) wherehierarchically encoded service indicators are used to indicate whenservice is needed.

2. Description of Related Art

Service indicators, such as LEDs, are typically used to help servicetechnicians locate the correct component to be repaired on a computersystem. On many small and mid-range computers, each field replaceableunit (FRU) has an unlabeled LED which represents the FRU that needs tobe repaired. The LED is physically mounted on the FRU itself or thesecond level package that includes the FRU. Therefore, the LED does notneed to be labeled since it is physically located on the FRU, or theFRU's outer package, that needs service. In these systems, there is aone-to-one correspondence between each FRU and the indicator thatrepresents the FRU. Thus, in these systems, each FRU is associated withand represented by its own LED.

On high end systems, because of the density of the package and number ofFRUs involved, a light strip is sometimes used to mount the LEDs in avisible location. Thus, instead of being mounted directly on the FRU orthe second level package that includes the FRU, each LED is mounted onthe light strip. The light strip includes an LED for each FRU in thesystem. In this example, there remains a one-to-one correspondencebetween FRUs and LEDs. Each individual FRU is associated with andrepresented by its own LED.

In some high end systems, all of these LEDs could total in the hundreds.This creates many problems. The light strip must be very large andlocated somewhere close to the central processing complex that includesthe processing nodes, but not in the way of service technicians orairflow for cooling. There may be problems with lighting this largenumber of LEDs in standby mode of operation. And, it may be hard for theservice technician to distinguish which LED is associated with which FRUbecause of the large number of LEDs. This then defeats the purpose ofhaving LEDs.

In addition to the LED that indicates whether a particular FRU needsservice, other indicators may be used to indicate whether a particularFRU is currently receiving power. Thus, each individual FRU will haveone or more indicators that represent its status. When the power statusof an FRU is to be indicated, the FRU will have two indicatorsassociated with it, one to indicate service and one to indicate powerstatus.

Some FRUs support concurrent replacement. Concurrent replacement meansthat an FRU may be replaced while the system is running. It isimperative that a service technician know the status of the power on theFRU before attempting to replace it. If the power is not in the correctstate and the service technician attempts to replace the FRU, it couldcause the system to checkstop and crash for what would otherwise havebeen a concurrent repair.

Therefore, a need exists for a method, system, and product indicatingpower status for field replaceable units (FRUs) where hierarchicallyencoded service indicators are used to indicate when service is needed.

SUMMARY OF THE INVENTION

A method, system, and product are disclosed for indicating a powerstatus of multiple devices using hierarchically encoded indicators.Multiple nodes are included within a data processing system. Each nodeincludes a different implementation of the devices. Each one of a firstlevel of power indicators are associated with a different one of thenodes. Each one of a second level of power indicators are associatedwith a different one of the devices. A power status of each node isindicated utilizing one of the first level of power indicators. A powerstatus of each device is indicated utilizing the second level of powerindicators.

The above as well as additional objectives, features, and advantages ofthe present invention will become apparent in the following detailedwritten description.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features believed characteristic of the invention are setforth in the appended claims. The invention itself, however, as well asa preferred mode of use, further objectives and advantages thereof, willbest be understood by reference to the following detailed description ofan illustrative embodiment when read in conjunction with theaccompanying drawings, wherein:

FIG. 1 is a block diagram of a data processing system in which thepresent invention may be implemented in accordance with the presentinvention;

FIG. 2 is a block diagram of an exemplary logically partitioned platformin which the present invention may be implemented in accordance with thepresent invention;

FIG. 3 depicts a block diagram of a computer system including a nodeenclosure and I/O drawers in accordance with the present invention;

FIG. 4 illustrates a more detailed block diagram of a node enclosure inaccordance with the present invention;

FIG. 5 depicts a more detailed block diagram of a node in accordancewith the present invention;

FIG. 6 illustrates a block diagram of a front panel indicator panel forindicating when FRUs need to be serviced in accordance with the presentinvention;

FIG. 7 illustrates a block diagram of a back panel indicator panel forindicating when FRUs need to be serviced in accordance with the presentinvention;

FIG. 8 depicts a high level flow chart that illustrates monitoring thecurrent power status for each node, and for each FRU that supportsreplacement during system operation in accordance with the presentinvention;

FIG. 9 illustrates a high level flow chart that depicts setting a powerindicator for a node in accordance with the present invention;

FIG. 10 depicts a high level flow chart that illustrates setting a powerindicator for a particular type of FRU that supports replacement duringsystem operation in accordance with the present invention; and

FIG. 11 illustrates a high level flow chart that depicts commanding thepower indicators to indicate current power status for a specified nodein accordance with the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

A preferred embodiment of the present invention and its advantages arebetter understood by referring to the figures, like numerals being usedfor like and corresponding parts of the accompanying figures.

The present invention is a method, system, and product usinghierarchically encoding indicators to indicate the present power statusof devices. A plurality of nodes is provided. Each node includes animplementation of a set of devices. These devices are preferably fieldreplaceable units (FRUs). Thus, multiple different sets of the same FRUsexist, one in each node. The present invention provides first levelindicators that are associated with the nodes. Second level indicatorsare also provided that are associated with the FRUs in the nodes.

Each first level indicator is associated with a different node. Eachsecond level indicator is associated with and represents a particularFRU included in the set for all nodes. Thus, a single second levelindicator is associated with and represents multiple FRUs. Each secondlevel indicator represents one of the FRUs of the set for each node.Therefore, if there are four nodes, each having a set of the same FRUs,the second level indicators will each represent four FRUs, one FRU ofthe set in each node.

The indicators are preferably implemented using LEDs, although anysuitable type of indicator may be used. At the node level, each firstlevel indicator indicates the power status of the FRUs included in thatnode. If none of the FRUs are receiving power, the LED associated withand representing this node will be deactivated by turning the LED off.If at least one of the FRUs in the node is receiving power, the LED thatis associated with this node will be activated by turning the LED on.

At the device, or FRU, level, the second level indicators will eachindicate the power status for the associated FRUs in all nodes. Forexample, if a particular FRU in the set of FRUs is receiving power ineach one of the nodes, i.e. the four FRUs are all presently receivingpower, the second level indicator that is associated with thisparticular FRU will be activated. If none of the FRUs in any of thenodes is receiving power, the second level indicator will bedeactivated. And, if at least one but not all of the FRUs is receivingpower, the second level indicator will be partially activated, such asby causing the LED to blink.

A first type of indicator is described herein as an identity indicator.A second type of indicator is described herein as a power indicator. Thepower indicators include a first level indicator for indicating power ata node level and a second level indicator for indicating power at a FRUlevel. A hierarchical indicator is also described that may be used inconjunction with the identity indicators for identifying particularinstances of actual FRUs.

FIG. 1 depicts a block diagram of a data processing system in which thepresent invention may be implemented in accordance with the presentinvention. Data processing system 100 may be a symmetric multiprocessor(SMP) system including a plurality of processors 102, 103, 104, and 105connected to a bus 106. For example, data processing system 100 may bean IBM eServer pSeries, a product of International Business MachinesCorporation in Armonk, N.Y. Data processing system 100 includes acentral electronic complex (CEC) 101 which may include logicallypartitioned hardware. CEC 101 includes a plurality of processors 102,103, 104, and 105 connected to system bus 106. Alternatively, a singleprocessor system may be employed. Also connected to system bus 106 ismemory controller/cache 108, which provides an interface to a pluralityof local memories 160–163. RIO Hub 110 is connected to system bus 106and provides an interface to RIO bus 112. Memory controller/cache 108and RIO Hub 110 may be integrated as depicted.

Data processing system 100 may be a logically partitioned dataprocessing system. Thus, data processing system 100 may have multipleheterogeneous operating systems (or multiple instances of a singleoperating system) running simultaneously. Each of these multipleoperating systems may have any number of software programs executingwithin it. Data processing system 100 may be logically partitioned suchthat different PCI slots, to which PCI I/O adapters may be coupled mayeach be assigned to different logical partitions. In this case, graphicsadapter 148 provides a connection for a display device (not shown),while hard disk adapter 149 provides a connection to control hard disk150.

Remote Input/Output (RIO) to PCI bridge 114 is connected to RIO bus 112and provides an interface to PCI bus 117 and PCI bus 118. RIO to PCIbridge 114 includes one or more PCI host bridges (PHB), such as PHB 115and PHB 116. Each PHB is coupled to a PCI to PCI bridge through a PCIbus. For example, PHB 115 is coupled to PCI to PCI bridge 119 throughPCI bus 117. PHB 116 is coupled to PCI to PCI bridge 126 through PCI bus118.

An I/O device may be coupled to data processing system 100 utilizing anI/O adapter. For example, as depicted, I/O device 123 is coupled to I/Oadapter 125.

A memory mapped graphics adapter 148 may be connected to RIO bus 112through PCI bus 144, EADS 142, PCI bus 141, and RIO to PCI bridge 140. Ahard disk 150 may be coupled to hard disk adapter 149 which is connectedto PCI bus 145. In turn, this bus is connected to EADS 142, which isconnected to RIO to PCI Bridge 140 by PCI bus 141.

An RIO to PCI bridge 132 provides an interface for a PCI bus 133 toconnect to RIO bus 112. PCI I/O adapter 136 is connected to EADS 134 byPCI bus 135. EADS 132 is connected to PCI bus 133. This PCI bus alsoconnects RIO to PCI bridge 132 to the service processor mailboxinterface and ISA bus access pass-through logic 194 and PCI-to-PCIbridge 132. Service processor mailbox interface and ISA bus accesspass-through logic 194 forwards PCI accesses destined to the PCI/ISAbridge 193. NVRAM storage 192 is connected to the ISA bus 196. Serviceprocessor 135 is coupled to service processor mailbox interface and ISAbus access pass-through logic 194 through its local PCI bus 195. Serviceprocessor 135 is also connected to processors 102–105 via a plurality ofJTAG/I²C busses 134. JTAG/I²C busses 134 are a combination of JTAG/scanbusses (see IEEE 1149.1) and Phillips I²C busses. However,alternatively, JTAG/I²C busses 134 may be replaced by only Phillips I²Cbusses or only JTAG/scan busses. All SP-ATTN signals of the hostprocessors 102, 103, 104, and 105 are connected together to an interruptinput signal of the service processor. The service processor 135 has itsown local memory 191, and has access to the hardware OP-panel 190.

Data processing system 100 may be implemented using various commerciallyavailable computer systems. For example, data processing system 100 maybe implemented using IBM eServer pSeries system available fromInternational Business Machines Corporation. Such a system may supportlogical partitioning using an AIX, which is also available fromInternational Business Machines Corporation.

Those of ordinary skill in the art will appreciate that the hardwaredepicted in FIG. 1 may vary. For example, other peripheral devices, suchas optical disk drives and the like, also may be used in addition to orin place of the hardware depicted. The depicted example is not meant toimply architectural limitations with respect to the present invention.

With reference now to FIG. 2, a block diagram of an exemplary logicallypartitioned platform is depicted in which the present invention may beimplemented. The hardware in logically partitioned platform 200 may beimplemented as, for example, data processing system 100 in FIG. 1.Logically partitioned platform 200 includes partitioned hardware 230,operating systems 202, 204, 206, 208, and hypervisor 210. Operatingsystems 202, 204, 206, and 208 may be multiple copies of a singleoperating system or multiple heterogeneous operating systemssimultaneously run on platform 200. These operating systems may beimplemented using AIX which are designed to interface with a hypervisor.Operating systems 202, 204, 206, and 208 are located in partitions 203,205, 207, and 209. Additionally, these partitions also include firmwareloaders and partition support 211, 213, 215, and 217. When partitions203, 205, 207, and 209 are instantiated, a copy of the open firmware isloaded into each partition by the hypervisor's partition manager. Theprocessors associated or assigned to the partitions are then dispatchedto the partitions' memory to execute the partition firmware.

Partitioned hardware 230 includes a plurality of processors 232–238, aplurality of system memory units 240–246, a plurality of input/output(I/O) adapters 248–262, and a storage unit 270. Partitioned hardware 230also includes service processor 290, which may be used to providevarious services, such as processing of errors in the partitions. Eachof the processors 232–238, memory units 240–246, NVRAM storage 298, andI/O adapters 248–262 may be assigned to one of multiple partitionswithin logically partitioned platform 200, each of which corresponds toone of operating systems 202, 204, 206, and 208.

Partition management firmware (hypervisor) 210 performs a number offunctions and services for partitions 203, 205, 207, and 209 to createand enforce the partitioning of logically partitioned platform 200.Hypervisor 210 is a firmware implemented virtual machine identical tothe underlying hardware. Hypervisor software is available fromInternational Business Machines Corporation. Firmware is “software”stored in a memory chip that holds its content without electrical power,such as, for example, read-only memory (ROM), programmable ROM (PROM),erasable programmable ROM (EPROM), electrically erasable programmableROM (EEPROM), and non-volatile random access memory (non-volatile RAM).Thus, hypervisor 210 allows the simultaneous execution of independent OSimages 202, 204, 206, and 208 by virtualizing all the hardware resourcesof logically partitioned platform 200.

FIG. 3 depicts a block diagram of a computer system 300 including a nodeenclosure 302 and I/O drawers 304–310 in accordance with the presentinvention. Computer system 300 may communicate with other systems viaone or more of the I/O drawers 304–310.

FIG. 4 illustrates a more detailed block diagram of node enclosure 302in accordance with the present invention. Node enclosure 302 includesmultiple nodes 402–408, multiple cooling units 410–420, and multiplepower units 422–444. Cooling units 410–420 and power units 422–444 areused to cool and power nodes 402–408.

FIG. 5 depicts a more detailed block diagram of a node 500 in accordancewith the present invention. Node 500 may be used to implement any ofnodes 402–408. Node 500 includes a planar card Px on which are connectedprocessors C26 and C27, memory DIMMs C14–C25, various I/O cards andadapters C5–C13, and redundant clocks and service processors C1–C4. EachPx and C1–C27 device in each node is an individual field replaceableunit (FRU). Therefore, each one of the Px and C1–C27 FRUs needs to beassociated with an identity indicator that indicates when the actual FRUneeds to be serviced, such as by being replaced or repaired.

The set of Px and C1–C27 FRUs is replicated throughout nodes 402–408.There is a separate set of Px and C1–C27 FRUs in each node 402–408.

FIG. 6 illustrates a block diagram of a front panel indicator panel 600for indicating when FRUs need to be serviced in accordance with thepresent invention. FIG. 7 illustrates a block diagram of a back panelindicator panel 700 for indicating when FRUs need to be serviced inaccordance with the present invention. The identity indicators includedin panels 600 and 700 are labeled according to the FRU they areassociated with in order to assist a service technician in quicklyidentifying and locating an actual FRU that requires service.

Indicator panels 600 and 700 include an identity indicator, such as anamber LED, associated with the FRUs in a node enclosure. Some amberidentity indicators represent only one actual FRU, while other amberidentity indicators represent several FRUs. There are some FRUs, such asthe clock, service processor, and power supplies, where there aremultiple instances of the same FRU where each instance of the FRU isassociated with its own amber indicator. Thus, there is a one-to-oneassociation between indicators and FRUs for some FRUs, while there is aone-to-many association between other indicators and the FRUs that theyrepresent.

There are several identical sets of Px and C1–C27 FRUs in node enclosure302. There is a separate set of Px and C1–C27 FRUs in each node 402–408.The present invention provides for only one amber identity indicator foreach FRU in the set. Thus, there are 28 indicators, one for each of Pxand C1–C27. These 28 indicators are used to indicate a Px or C1–C27 FRUno matter what node includes the actual FRU. Therefore, these indicatorsindicate which FRU in a set requires service but does not indicate theactual FRU that needs service. For these indicators, there is aone-to-many relationship between an indicator and FRUs.

For example, if the amber indicator that is associated with andrepresents the C5 FRU is activated, a service technician will know thata C5 FRU needs to be replaced. The service technician does not know,just by looking at the single C5 FRU indicator, which actual C5 FRUneeds to be replaced. The technician does not know which node includesthe C5 FRU that needs to be replaced.

In order to identify an actual FRU that needs to be replaced, thepresent invention provides for hierarchical indicators in addition tothe identity indicators. There is a hierarchical indicator for eachlevel of hierarchy provided. In the present invention, there are twohierarchy levels. There is a set level having the 28 identityindicators, and a node level have four indicators. By looking to thecombination of identity and hierarchy indicators, a technician maylocate the actual FRU that needs service.

For example, the 28 identity indicators are provided as Px and C1–C27.In addition, hierarchy indicators 602, 604, 606, and 608 are provided.The hierarchy indicators 602, 604, 606, and 608 are used in conjunctionwith the 28 identity indicators in order to identify an actual FRU. Oneof the identity indicators will be activated to identify one of the FRUsof the set. And, in order to identify the actual FRU that needs service,one of the hierarchy indicators 602, 604, 606, and 608 will be activatedsimultaneously. For example, if the C6 FRU in P4 node 406 needs service,amber identity indicator 612 and amber identity indicator 606 will bothbe activated simultaneously.

Some identity indicators represent just one actual FRU. For example,amber indicators A1–A6 (see FIGS. 6 and 7) are associated with andindicate whether cooling units 410–420 need service. Amber indicator A1is associated with cooling unit 410. Amber indicator A2 is associatedwith cooling unit 412. Amber indicator A3 is associated with coolingunit 414. Amber indicator A4 is associated with cooling unit 416. Amberindicator A5 is associated with cooling unit 418. And, amber indicatorA6 is associated with cooling unit 420.

As another example, there are twelve separate power units 422–444depicted in node enclosure 302. There is a one-to-one correspondencebetween E1–E12 indicators and power units 422–444. Amber indicator E1 isassociated with and indicates whether power unit 422 needs service.Amber indicator E2 is associated with and indicates whether power unit424 needs service. Amber indicator E3 is associated with and indicateswhether power unit 426 needs service. Amber indicator E4 is associatedwith and indicates whether power unit 428 needs service. Amber indicatorE5 is associated with and indicates whether power unit 430 needsservice. Amber indicator E6 is associated with and indicates whetherpower unit 432 needs service. Amber indicator E7 is associated with andindicates whether power unit 434 needs service. Amber indicator E8 isassociated with and indicates whether power unit 436 needs service.Amber indicator E9 is associated with and indicates whether power unit438 needs service. Amber indicator E10 is associated with and indicateswhether power unit 440 needs service. Amber indicator E11 is associatedwith and indicates whether power unit 442 needs service. And, amberindicator E12 is associated with and indicates whether power unit 444needs service.

Some identity indicators represent multiple FRUs. Some sets of FRUs arefound in more than one node in node enclosure 302. Thus, a set of FRUsmay be replicated in node enclosure 302 such that several nodes includeone of these sets of FRUs. As described above, the present inventionprovides a set of amber indicators where each amber indicator in the setrepresents an FRU included in the set of FRUs. Each one of these amberindicators then represents a particular FRU but does not by itselfindicate an actual FRU in a particular node. These amber indicators donot indicate by themselves which set includes an FRU represented by theindicator. Thus, when one of the amber indicators is activated, itindicates that an FRU needs service, but does not indicate which set ofFRUs includes the FRU that needs service. In addition to the set ofamber indicators, there are hierarchical indicators that indicate whichset includes an actual FRU that needs service. Thus, for sets of FRUsthat are replicated throughout the node enclosure, there is aone-to-many relationship between amber indicators and actual FRUs.

For example, each node includes a set of FRUs C1–C27. Instead ofproviding 112 different indicators which would be required for a systemhaving 28 indicators repeated in four different nodes, the presentinvention provides for only 32 indicators. Thus the indicators in box601 indicate the status of the FRUs in the set of FRUs found in eachnode. When one of these indicators is activated, it means that a FRUneeds service in one of the nodes. In order to determine which nodeincludes the actual FRU that needs service, a hierarchical amberindicator is included for each node. Thus, amber indicator P2 602 isassociated with node 402. Amber indicator P3 604 is associated with node404. Amber indicator P4 606 is associated with node 406. And, amberindicator P5 608 is associated with node 408.

An amber indicator is provided for set of FRUs C1–C27 and for the planaritself Px. For example, amber indicator C1 610 is provided and indicateswhether the FRU C1 needs service on one of the nodes P2–P5 402–408.Amber indicator C6 612 is provided and indicates whether the FRU C6needs service on one of the nodes P2–P5 402–408. And, amber indicatorC11 622 is provided and indicates whether the FRU C11 needs service onone of the nodes P2–P5 402–408. Amber indicator Px 616 is provided andindicates whether one of the planars needs service.

When an FRU on one of the nodes needs service, the amber indicator thatis associated with that FRU is activated. For example, if FRU C6 on nodeP4 406 needs service, amber indicator 612 is activated. According to thepresent invention, indicators 602–608 for nodes 402–408 are used toindicate which node 402–408 includes the particular FRU that needsservice. In this example, amber indicator P4 606 will be activated. Inthis manner, indicator 612 indicates that a C6 FRU needs to be serviced,and indicator 606 is used to indicate that the actual C6 FRU that needsservice is located on node 406.

The present invention also provides for a set of green power indicatorsthat indicate whether an FRU is currently receiving power. Some of theFRUs may be replaced while the system is running However, it is stillimportant to know whether the FRU is currently receiving power prior toattempting to replace the FRU. For the FRUs that are of a type whichpermit replacement while the system is running, a green power indicatoris also provided.

For example, the C1, C3, C5, C6, C8, C9, C11, and C13 FRUs are types ofFRUs that can be replaced while the system is running. For example,green power indicator 618 indicates whether any of the C1 FRUs arecurrently receiving power in any of the nodes 402–408. Green powerindicator 620 indicates whether any of the C6 FRUs are currentlyreceiving power in any of the nodes 402–408. And, green power indicator626 indicates whether any of the C11 FRUs are currently receiving powerin any of the nodes 402–408.

The present invention provides for use of the green power indicators intwo ways. The green power indicators of panels 600 and 700 may be lit toindicate whether any of the nodes 402–408 and FRUs are receiving power.Thus, a green power indicator of box 601 will be activated if the FRUsrepresented by that green power indicator in each node are currentlyreceiving power. If none of the FRUs represented by that green powerindicator are receiving power in any of the nodes, its green powerindicator will be off. If at least one FRU but not all of the FRUsrepresented by the green power indicator are receiving power, the greenpower indicator will blink.

Green power indicators 624–630 are used to indicate whether power ispresent on any of the FRUs included in the node associated with theindicator. Power indicator 624 will be activated if there is a voltagepresent on any of the FRUs included in node P2 402. Power indicator 626will be activated if there is a voltage present on any of the FRUsincluded in node P3 404. Power indicator 628 will be activated if thereis a voltage present on any of the FRUs included in node P4 406. And,power indicator 630 will be activated if there is a voltage present onany of the FRUs included in node P5 408.

A second method for using the green power indicators is to select justone node to evaluate. Thus, in this case, the panels 600 and 700 are setby a command to indicate only one node as described below.

For example, a service technician may wish to see the power status forthe FRUs of node P3 404 which may be replaced while the system isrunning. A command will be sent from a microcontroller that is executingthe present invention to panels 600 and 700 causing the panels' greenpower indicators to indicate power status for node P3 404. In this case,a green power indicator of box 601 will be on if the FRU in node P3 thatis represented by the green power indicator is receiving power and offif it is not.

FIG. 8 depicts a high level flow chart that illustrates monitoring thecurrent power status for each node, and for each FRU that supportsreplacement during system operation in accordance with the presentinvention. The process starts as depicted by block 800 and thereafterpasses to block 802 which illustrates monitoring the power status foreach node, and for each FRU that supports replacement during systemoperation for each node, using the I2C bus. Next, block 804 depictsactivating the power status indicators, such as by illuminating thegreen LEDs, according to the processes depicted by FIGS. 9–11.

FIG. 9 illustrates a high level flow chart that depicts setting a powerindicator for a node in accordance with the present invention. Theprocess starts as illustrated by block 900 and thereafter passes toblock 902 which depicts a determination of whether or not the power isoff for all FRUs for this particular node. If a determination is madethat the power is not off for all FRUs for this node, the process passesto block 904 which illustrates activating the power status indicator,such as by illuminating the green LED, that is associated with thisnode. The process then passes back to block 902.

Referring again to block 902, if a determination is made that the poweris off for all FRUs for this node, the process passes to block 906 whichdepicts deactivating the power status indicator, such as by turning thegreen LED off, that is associated with this node. The process thenpasses back to block 902.

FIG. 10 depicts a high level flow chart that illustrates setting a powerindicator for a particular FRU that supports replacement during systemoperation in accordance with the present invention. The process depictedby FIG. 10 is repeated for each FRU position in the node that supportsreplacement during system operation.

The process starts as depicted by block 1000 and thereafter passes toblock 1002 which illustrates a determination of whether or not the poweris off for all FRUs represented by a particular power status indicatorin all nodes. If a determination is made that power is off for all FRUsrepresented by a particular power status indicator in all nodes, theprocess passes to block 1004 which depicts deactivating the power statusindicator, such as by turning the green LED off. The process then passesback to block 1002.

Referring again to block 1002, if a determination is made that power isnot off for all FRUs represented by the particular power statusindicator in all nodes, the process passes to block 1006 which depicts adetermination of whether or not power is on for all FRUs represented bythe particular power status indicator in all nodes. If a determinationis made that power is on for all FRUs represented by the particularpower status indicator in all nodes, the process passes to block 1008which illustrates activating the power status indicator, such as byturning the green LED on. The process then passes back to block 1002.

Referring again to block 1006, if a determination is made that power isnot on for all FRUs represented by the particular power status indicatorin all nodes, the process passes to block 1010 which illustrates causingthe power status indicator, such as the green LED, to blink. The processthen passes back to block 1002.

FIG. 11 illustrates a high level flow chart that depicts commanding thepower indicators to indicate current power status for a specified nodein accordance with the present invention. The process starts asillustrated by block 1100 and thereafter passes to block 1102 whichdepicts specifying a particular node. Next, block 1104 illustratesdetermining the power status of the selected node and for all FRUs inthat node that support replacement during system operation. Thereafter,block 1106 depicts turning the power status indicators, i.e. the greenpower indicators, for each FRU in the node that supports replacementduring system operation either on or off according to its particularcurrent power status. Next, the process passes to block 1108 whichdepicts a determination of whether or not the power is off for all FRUsfor this particular node. If a determination is made that the power isnot off for all FRUs for this node, the process passes to block 1110which illustrates activating the second type of indicator, such as byilluminating the green LED, that is associated with this node. Theprocess then passes back to block 1102.

Referring again to block 1108, if a determination is made that the poweris off for all FRUs for this node, the process passes to block 1112which depicts deactivating the second type of indicator, such as byturning the green LED off, that is associated with this node. Theprocess then passes back to block 1102.

It is important to note that while the present invention has beendescribed in the context of a fully functioning data processing system.Those of ordinary skill in the art will appreciate that the processes ofthe present invention are capable of being distributed in the form of acomputer readable medium of instructions and a variety of forms and thatthe present invention applies equally regardless of the particular typeof signal bearing media actually used to carry out the distribution.Examples of computer readable media include recordable-type media, suchas a floppy disk, a hard disk drive, a RAM, CD-ROMs, DVD-ROMs, andtransmission-type media, such as digital and analog communicationslinks, wired or wireless communications links using transmission forms,such as, for example, radio frequency and light wave transmissions. Thecomputer readable media may take the form of coded formats that aredecoded for actual use in a particular data processing system.

The description of the present invention has been presented for purposesof illustration and description, and is not intended to be exhaustive orlimited to the invention in the form disclosed. Many modifications andvariations will be apparent to those of ordinary skill in the art. Theembodiment was chosen and described in order to best explain theprinciples of the invention, the practical application, and to enableothers of ordinary skill in the art to understand the invention forvarious embodiments with various modifications as are suited to theparticular use contemplated.

1. A method in a data processing system for indicating a power status ofa plurality of devices using hierarchically encoded indicators, saidmethod comprising the steps of: providing a plurality of nodes, each oneof said plurality of nodes including a different implementation of saidplurality of devices; associating each one of a first level of powerindicators with a different one of said plurality of nodes, each one ofsaid first level of power indicators representing one of said pluralityof nodes; associating each one of a second level of power indicatorswith a different one of said plurality of devices, each one of saidsecond level of power indicators simultaneously representing a device ineach one of said plurality of nodes; indicating a power status of saidplurality of nodes utilizing said first level of power indicators; andindicating a power status of said plurality of devices utilizing saidsecond level of power indicators.
 2. The method according to claim 1,further comprising: said plurality of devices being a plurality of fieldreplaceable units (FRUs).
 3. The method according to claim 2, furthercomprising: determining a power status for each one of said plurality ofFRUs included in a first one of said plurality of nodes; in response todetermining that none of said plurality of FRUs included in a first oneof said plurality of nodes are receiving power, deactivating said firstlevel of power indicators; and in response to determining that at leastone of said plurality of FRUs included in a first one of said pluralityof nodes is receiving power, activating said first level of powerindicators.
 4. The method according to claim 3, further comprising:determining a power status for said one of said plurality of devices ineach one of said plurality of nodes; and indicating said power statusfor said one of said plurality of devices in each one of said pluralityof nodes utilizing one of said second level of power indicators that isassociated with said one of said plurality of devices.
 5. The methodaccording to claim 4, further comprising: determining whether each oneof said plurality of devices in each one of said plurality of nodes isreceiving power; in response to determining that none of said pluralityof devices in each one of said plurality of nodes is receiving power,deactivating said one of said second level of power indicators that isassociated with said one of said plurality of devices; in response todetermining that each one of said plurality of devices in each one ofsaid plurality of nodes is receiving power, activating said one of saidsecond level of power indicators that is associated with said one ofsaid plurality of devices; and in response to determining that at leastone but not all of said plurality of devices in each one of saidplurality of nodes is receiving power, partially activating said one ofsaid second level of power indicators that is associated with said oneof said plurality of devices.
 6. The method according to claim 5,further comprising: said one of said second level of power indicatorsbeing an LED; said step of deactivating said one of said second level ofpower indicators further including turning said LED off; said step ofactivating said one of said second level of power indicators furtherincluding turning said LED on; and said step of partially activatingsaid one of said second level of power indicators further includingcausing said LED to blink.
 7. The method according to claim 1, furthercomprising: selecting one of said plurality of nodes; determining apower status for each one of said plurality of devices included in saidselected one of said plurality of nodes; associating each one of saidsecond level of power indicators with a different one of said pluralityof devices included in said selected one of said plurality of nodes; andindicating said determined power status for each one of said pluralityof devices included in said selected one of said plurality of nodesutilizing said second level of power indicators.
 8. A data processingsystem for indicating a power status of a plurality of devices usinghierarchically encoded indicators, comprising: a plurality of nodes,each one of said plurality of nodes including a different implementationof said plurality of devices; a first level of power indicators, eachone of said first level of power indicators being associated with adifferent one of said plurality of nodes, each one of said first levelof power indicators representing one of said plurality of nodes; asecond level of power indicators, each one of said second level of powerindicators being associated with a different one of said plurality ofdevices, each one of said second level of power indicatorssimultaneously representing a device in each one of said plurality ofnodes; said first level of power indicators for indicating a powerstatus of said plurality of nodes; and said second level of powerindicators for indicating a power status of said plurality of devices.9. The system according to claim 8, further comprising: said pluralityof devices being a plurality of field replaceable units (FRUs).
 10. Thesystem according to claim 9, further comprising: said system including aCPU executing code for determining a power status for each one of saidplurality of FRUs included in a first one of said plurality of nodes; inresponse to determining that none of said plurality of FRUs included ina first one of said plurality of nodes are receiving power, said CPUexecuting code for deactivating said first level of power indicators;and in response to determining that at least one of said plurality ofFRUs included in a first one of said plurality of nodes is receivingpower, said CPU executing code for activating said first level of powerindicators.
 11. The system according to claim 10, further comprising:said CPU executing code for determining a power status for said one ofsaid plurality of devices in each one of said plurality of nodes; andsaid CPU executing code for indicating said power status for said one ofsaid plurality of devices in each one of said plurality of nodesutilizing one of said second level of power indicators that isassociated with said one of said plurality of devices.
 12. The systemaccording to claim 11, further comprising: said CPU executing code fordetermining whether each one of said plurality of devices in each one ofsaid plurality of nodes is receiving power; in response to determiningthat none of said plurality of devices in each one of said plurality ofnodes is receiving power, said CPU executing code for deactivating saidone of said second level of power indicators that is associated withsaid one of said plurality of devices; in response to determining thateach one of said plurality of devices in each one of said plurality ofnodes is receiving power, said CPU executing code for activating saidone of said second level of power indicators that is associated withsaid one of said plurality of devices; and in response to determiningthat at least one but not all of said plurality of devices in each oneof said plurality of nodes is receiving power, said CPU executing codefor partially activating said one of said second level of powerindicators that is associated with said one of said plurality ofdevices.
 13. The system according to claim 12, further comprising: saidone of said second level of power indicators being an LED; said CPUexecuting code for deactivating said one of said second level of powerindicators further including turning said LED off; said CPU executingcode for activating said one of said second level of power indicatorsfurther including turning said LED on; and said CPU executing code forpartially activating said one of said second level of power indicatorsfurther including causing said LED to blink.
 14. The system according toclaim 8, further comprising: said CPU executing code for selecting oneof said plurality of nodes; said CPU executing code for determining apower status for each one of said plurality of devices included in saidselected one of said plurality of nodes; said CPU executing code forassociating each one of said second level of power indicators with adifferent one of said plurality of devices included in said selected oneof said plurality of nodes; and said CPU executing code for indicatingsaid determined power status for each one of said plurality of devicesincluded in said selected one of said plurality of nodes utilizing saidsecond level of power indicators.
 15. A computer program product onrecordable medium for indicating a power status of a plurality ofdevices using hierarchically encoded indicators, said productcomprising: instruction means for associating each one of a first levelof power indicators with a different one of said plurality of nodes,each one of said plurality of nodes including a different implementationof said plurality of devices and each one of said first level of powerindicators representing one of said plurality of nodes; instructionmeans for associating each one of a second level of power indicatorswith a different one of said plurality of devices, each one of saidsecond level of power indicators simultaneously representing a device ineach one of said plurality of nodes; instruction means for indicating apower status of said plurality of nodes utilizing said first level ofpower indicators; and instruction means for indicating a power status ofsaid plurality of devices utilizing said second level of powerindicators.
 16. The product according to claim 15, further comprising:said plurality of devices being a plurality of field replaceable units(FRUs).
 17. The product according to claim 16, further comprising:instruction means for determining a power status for each one of saidplurality of FRUs included in a first one of said plurality of nodes; inresponse to determining that none of said plurality of FRUs included ina first one of said plurality of nodes are receiving power, instructionmeans for deactivating said first level of power indicators; and inresponse to determining that at least one of said plurality of FRUsincluded in a first one of said plurality of nodes is receiving power,instruction means for activating said first level of power indicators.18. The product according to claim 17, further comprising: instructionmeans for determining a power status for said one of said plurality ofdevices in each one of said plurality of nodes; and instruction meansfor indicating said power status for said one of said plurality ofdevices in each one of said plurality of nodes utilizing one of saidsecond level of power indicators that is associated with said one ofsaid plurality of devices.
 19. The product according to claim 18,further comprising: instruction means for determining whether each oneof said plurality of devices in each one of said plurality of nodes isreceiving power; in response to determining that none of said pluralityof devices in each one of said plurality of nodes is receiving power,instruction means for deactivating said one of said second level ofpower indicators that is associated with said one of said plurality ofdevices; in response to determining that each one of said plurality ofdevices in each one of said plurality of nodes is receiving power,instruction means for activating said one of said second level of powerindicators that is associated with said one of said plurality ofdevices; and in response to determining that at least one but not all ofsaid plurality of devices in each one of said plurality of nodes isreceiving power, instruction means for partially activating said one ofsaid second level of power indicators that is associated with said oneof said plurality of devices.
 20. The product according to claim 19,further comprising: said one of said second level of power indicatorsbeing an LED; said instruction means for deactivating said one of saidsecond level of power indicators further including instruction means forturning said LED off; said instruction means for activating said one ofsaid second level of power indicators further including instructionmeans for turning said LED on; and said instruction means for partiallyactivating said one of said second level of power indicators furtherincluding instruction means for causing said LED to blink.
 21. Theproduct according to claim 15, further comprising: instruction means forselecting one of said plurality of nodes; instruction means fordetermining a power status for each one of said plurality of devicesincluded in said selected one of said plurality of nodes; instructionmeans for associating each one of said second level of power indicatorswith a different one of said plurality of devices included in saidselected one of said plurality of nodes; and instruction means forindicating said determined power status for each one of said pluralityof devices included in said selected one of said plurality of nodesutilizing said second level of power indicators.